ONOS-6225 Expose k-shortest path search as part of TopologyService.

Change-Id: Idf812a707aba0b972fcfbde871c624dfc86b6e1b
diff --git a/core/store/dist/src/main/java/org/onosproject/store/topology/impl/DistributedTopologyStore.java b/core/store/dist/src/main/java/org/onosproject/store/topology/impl/DistributedTopologyStore.java
index ffb5a95..585ed14 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/topology/impl/DistributedTopologyStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/topology/impl/DistributedTopologyStore.java
@@ -69,6 +69,7 @@
 import java.util.Objects;
 import java.util.Set;
 import java.util.stream.Collectors;
+import java.util.stream.Stream;
 
 import static com.google.common.base.Preconditions.checkArgument;
 import static org.onlab.util.Tools.get;
@@ -226,6 +227,22 @@
     }
 
     @Override
+    public Set<Path> getKShortestPaths(Topology topology,
+                                       DeviceId src, DeviceId dst,
+                                       LinkWeigher weigher,
+                                       int maxPaths) {
+        return defaultTopology(topology).getKShortestPaths(src, dst, weigher, maxPaths);
+    }
+
+    @Override
+    public Stream<Path> getKShortestPaths(Topology topology,
+                                          DeviceId src,
+                                          DeviceId dst,
+                                          LinkWeigher weigher) {
+        return defaultTopology(topology).getKShortestPaths(src, dst, weigher);
+    }
+
+    @Override
     public Set<DisjointPath> getDisjointPaths(Topology topology, DeviceId src, DeviceId dst) {
         return defaultTopology(topology).getDisjointPaths(src, dst);
     }